On Thu, Sep 17, 2020 at 08:00:55PM +0800, Peng Liang wrote:
> If we want to emulate ID registers, we need to initialize ID registers
> firstly. This commit is to add a helper function to traverse
> arm64_ftr_regs so that we can initialize ID registers from
> arm64_ftr_regs.
>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@xxxxxxxxxx>
> Signed-off-by: Peng Liang <liangpeng10@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/cpufeature.h | 2 ++
> arch/arm64/kernel/cpufeature.c | 13 +++++++++++++
> 2 files changed, 15 insertions(+)
>
> diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
> index 89b4f0142c28..2ba7c4f11d8a 100644
> --- a/arch/arm64/include/asm/cpufeature.h
> +++ b/arch/arm64/include/asm/cpufeature.h
> @@ -79,6 +79,8 @@ struct arm64_ftr_reg {
>
> extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0;
>
> +int arm64_cpu_ftr_regs_traverse(int (*op)(u32, u64, void *), void *argp);
> +
> /*
> * CPU capabilities:
> *
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index 6424584be01e..698b32705544 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -1112,6 +1112,19 @@ u64 read_sanitised_ftr_reg(u32 id)
> return regp->sys_val;
> }
>
> +int arm64_cpu_ftr_regs_traverse(int (*op)(u32, u64, void *), void *argp)
> +{
> + int i, ret;
> +
> + for (i = 0; i < ARRAY_SIZE(arm64_ftr_regs); i++) {
> + ret = (*op)(arm64_ftr_regs[i].sys_id,
> + arm64_ftr_regs[i].reg->sys_val, argp);
> + if (ret < 0)
> + return ret;
> + }
> + return 0;
> +}
> +
> #define read_sysreg_case(r) \
> case r: return read_sysreg_s(r)
>
> --
> 2.26.2
>
Skimming the rest of the patches to see how this is used I only saw a
single callsite. Why wouldn't we just put this simple for-loop right
there at that callsite? Or, IOW, I think this traverse function should
be dropped.
Thanks,
drew
